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FreeBSD can now boot in 25 milliseconds

theregister.com

31–40 of 52 posts

Re: FreeBSD can now boot in 25 milliseconds

#31
post #15

First line of article: Replacing a sort algorithm in the FreeBSD kernel has improved its boot speed by a factor of 100 or more This is obviously not true.

It's a bit of clonky writing, but in proper English "its boot speed" relates to the algorithm and not the FreeBSD kernel

Still doesn't really make sense, as the original algorithm is not 100x faster. The replacement is.

Re: FreeBSD can now boot in 25 milliseconds

#32

Having a tough time understanding the impacts of this work. Fast boot times matter if you boot often. So what’s the use case here? Hmm, actually I’m not sure I even understand the whole “serverless” thing that much to be honest. Running FreeBSD as if it’s a “process” on Linux is interesting in a way but - who does this?

[deleted]

Re: FreeBSD can now boot in 25 milliseconds

#33
post #28
post #17

If you fired a bullet at 450m/s at a FreeBSD machine sitting 50 feet away, it would have enough time to boot up and perform operations before being struck and destroyed by the bullet.

For ICBM test warheads they have a system that replaces the nuclear pit with a sensor package that measures the incoming shockfront, does signal processing and gets out a radio signal before the entire thing is crushed.

Does this have a name? A keyword I could search for? A wikipedia page?

Re: FreeBSD can now boot in 25 milliseconds

#34
post #28
post #17

If you fired a bullet at 450m/s at a FreeBSD machine sitting 50 feet away, it would have enough time to boot up and perform operations before being struck and destroyed by the bullet.

For ICBM test warheads they have a system that replaces the nuclear pit with a sensor package that measures the incoming shockfront, does signal processing and gets out a radio signal before the entire thing is crushed.

So if folks truly cared, it's possible to design a computer system to boot up, in a barebones fashion, and then do meaningful work and then transmit it, in under a millisecond?

Re: FreeBSD can now boot in 25 milliseconds

#35
post #28

Earlier quoted context omitted.

For ICBM test warheads they have a system that replaces the nuclear pit with a sensor package that measures the incoming shockfront, does signal processing and gets out a radio signal before the entire thing is crushed.

Does this have a name? A keyword I could search for? A wikipedia page?

High Explosive Radio Telemetry

Re: FreeBSD can now boot in 25 milliseconds

#36
post #28

Earlier quoted context omitted.

For ICBM test warheads they have a system that replaces the nuclear pit with a sensor package that measures the incoming shockfront, does signal processing and gets out a radio signal before the entire thing is crushed.

Does this have a name? A keyword I could search for? A wikipedia page?

Try "The Computer Designed To Die In Microseconds"

https://www.youtube.com/watch?v=FYdAT0v4DHs (Scott Manley)

https://www.lanl.gov/orgs/padwp/pdfs/2nwj2-03.pdf

Re: FreeBSD can now boot in 25 milliseconds

#37
post #28

Earlier quoted context omitted.

For ICBM test warheads they have a system that replaces the nuclear pit with a sensor package that measures the incoming shockfront, does signal processing and gets out a radio signal before the entire thing is crushed.

So if folks truly cared, it's possible to design a computer system to boot up, in a barebones fashion, and then do meaningful work and then transmit it, in under a millisecond?

Certainly, and I imagine that there are plenty that we interact with on a regular basis. For example, door security sensors (like for Ring) will be off nearly all the time. When someone opens the door, they will power up, send a notification, and go dormant again. I don't know if this will happen within a single millisecond, but it certainly could if there was a design need.

For many simple embedded systems that plug into the wall, the "boot" process will happen in under a millisecond. But it will take considerably longer than that for the voltage levels to stabilize.

The real thing which differentiates these from a PC or phone is that they are not running what we would typically call an OS. They may be running an RTOS (a very simplified OS), but for many of them, as soon as they have stable power, they are off to the races (Just like the home-computers of the 80s. Just plug in and go.)

Re: FreeBSD can now boot in 25 milliseconds

#38

> I believe Linux is at 75-80 ms for the same environment where I have FreeBSD booting in 25 ms. From the article, Colin Percival on how Linux does as well. Impressive (though would be good to see other benchmarks to corroborate Colin's). (Which is an HN comment actually: https://news.ycombinator.com/item?id=37205578 .)

I'm sure Colin's results can be reproduced, but it will take some effort. Colin has been doing a lot of work so that Firecracker can boot FreeBSD -- see https://www.daemonology.net/blog/2022-10-18-FreeBSD-Firecrac... for an introduction -- and that is not yet all available in Firecracker "out of the box."

Re: FreeBSD can now boot in 25 milliseconds

#39
post #28

Earlier quoted context omitted.

For ICBM test warheads they have a system that replaces the nuclear pit with a sensor package that measures the incoming shockfront, does signal processing and gets out a radio signal before the entire thing is crushed.

So if folks truly cared, it's possible to design a computer system to boot up, in a barebones fashion, and then do meaningful work and then transmit it, in under a millisecond?

I see you've never worked with microcontrollers.

Re: FreeBSD can now boot in 25 milliseconds

#40

Having a tough time understanding the impacts of this work. Fast boot times matter if you boot often. So what’s the use case here? Hmm, actually I’m not sure I even understand the whole “serverless” thing that much to be honest. Running FreeBSD as if it’s a “process” on Linux is interesting in a way but - who does this?

> Hmm, actually I’m not sure I even understand the whole “serverless” thing that much to be honest. A whole bunch of folks have given up on shared operating systems at a security, access control, data governance, and maintainability (reproducibility) level. At least if your goal is to create software for some purpose other than building server infrastructure. Some of them have decided that if you’re going to want thi…

So, why re-use a time sharing, multi-user OS to run your apps? Don't you just need a multi-core capable, POSIX environment?

Arguably POSIX doesn't really matter anymore does it? It's Linux or it doesn't matter in a lot of cases (sadly).

Seems like overkill. Sometimes optimal solutions are the available ones, sure, but is no one working on a POSIX exokernel "includeos" like thing?

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